In recent years, to increase the bandwidth of an amplifier, forming near a transistor a parallel inductor as a resonance circuit using a metal wire connected to the drain terminal and a capacitor prevails (see Patent Literature 1, for example). The resonance circuit is a circuit for reducing the influence of parasitic capacitance of the transistor (drain-source parasitic capacitance Cds), and is formed using the metal wire (inductor) and a pattern of a circuit board (capacitor).